How intermittent fasting works. And doesn’t.


This post is brought to you in partnership with Novant Health. All opinions are our own.

There are a lot of pseudoscientific diets out there that have many of us stressing about the food we eat these days. There are “detox” cleanses, the ever-so-popular keto diet and one of the hottest at the moment: intermittent fasting.

The basic premise is this: you can eat anything you want, but only during specific times or within a set calorie “budget.” And the idea isn’t exactly new. Dating back to the days of Hippocrates (around 460 to 370 B.C.), fasting was a form of treatment for seizures and other illnesses. Today it’s making a comeback with claims that it helps you not only lose weight, but also be more alert and productive.

What types of intermittent fasting plans are out there?

Intermittent fasting is an approach about which Andrea Hiatt, a registered dietitian with Novant Health Weight Loss Solutionsgets the most questions.

The range of fasting varies per individual, but the norm ranges from eight to 24 hours. Some fast for a window of a couple of hours to a full day a week. Others opt toward limiting their calorie intake to a few hundred calories during each fasting period.

She explained that similar to the keto diet, going without calories for long stretches of time can put your body into a state of ketosis, in which fat is burned instead of sugar for energy. In other words, insulin plays a huge role, in a way, that when insulin levels drop, so does your weight, cholesterol and blood sugar levels.

Up until a few years ago, the most promising research on intermittent fasting only involved very fat rats. For humans, there wasn’t much research that showed it to be more effective than any other meal plan out there. But in a recent study, researchers showed that not eating for 10 to 16 hours did improve weight loss results and insulin sensitivity. Another study, that looked at a group of obese men with prediabetes, found that intermittent fasting helped them dramatically lower their insulin levels, insulin sensitivity and blood pressure.

But Hiatt said intermittent fasting could be dangerous, especially if you’re prone to eating disorders.

“There are a lot of things that can go wrong when you’re skipping meals and not eating enough,” said Hiatt. This could turn into a binge eating disorder, when you skimp on meals and find yourself hoovering your fridge later.

Bottom line: Hiatt doesn’t recommend intermittent fasting as a solution for losing weight. While it might work for some, she said most of us can benefit from healthier eating patterns that aren’t necessarily too restrictive.

Short-term wins on fad diets almost always fade away. The most important way to see lasting results?

“Start changing your lifestyle by taking small steps to incorporate healthier habits into different areas of your life,” said Hiatt.

That could mean walking for 30 minutes a day, or substituting sugary juices with real fruit instead. Whatever it is, making incremental changes for the better can help you not just lose weight, but keep it from yo-yoing back.

The only way to find out, according to Hiatt, is not through guesswork from internet research, but rather through an informed discussion with your provider on whether fasting would help you move a step closer toward a healthier lifestyle.

Interested in transforming your diet? Chat with a provider on how you can make one healthier step forward. Find out how.


  1. TYPICAL CLICK BAIT… “How intermittent fasting works. And doesn’t”…Express your humanity for once by just presenting the facts which overwhelmingly supports the notion that intermittent fasting WORKS and HELP OTHERS not just yourself. You champion a misleading article title, we click, YOU GET PAID, we read WE GET MISLEAD and we loose. Really???

    • I concur with Messers Wayne and Afolabi, this is shameful clickbait. Please find a real job and stop creating mealy-mouthed FUD. Gee, someone who’s being paid by professional dietitians thinks diets are complicated and require paid professional advice? HOW SHOCKING

  2. I agree with the previous poster, Mr. Afolabi. Intermittent fasting allowed me to lose 27 lbs inside 2 months. Am healthier than I’ve ever been. To criticize it because a few OCD people might fail at it is stupid journalism. Don’t believe this Click-bait article!

  3. Why is it eating so many calories every day and remaining sedentary not considered an eating or lifestyle disorder when your body fat % gets out of control??

    I have just started to get through to the “other side” of my own personal weight loss journey. I catalog some of my thoughts and helpful resources on my website (Revoluthin dot com).

    One of the best things I stumbled upon was Intermittent Fasting (IF). At that time, I had actually lost a fair amount of weight, but didn’t look the best (skinny fat/average fat looks). Following a strict 0 calorie (water only, no tea, coffee, supplements nothing) 24-hour fast once every 3 days is what helped me lose about 10 lbs in less than 8 weeks.

    Since I had already lost the majority of “weight” at that point, I cared more about aesthetics. Also, my personal life at the time didn’t allow for much time at all to be spent exercising. So IF where I just had to focus my energies once every 3 days on NOT eating was a much better fit for my lifestyle and my fitness goals.

    I don’t use fancy calipers or other methods to track my BF%, just eyeball in the mirror, but I’d estimate I lost about 5% from IF alone in those first 8 weeks of trying it. And that’s with no exercise program whatsoever. Hard to beat relatively effortless results like that especially when you weigh your options of being in a calorie deficit 7 days a week and always hungry vs. just 1 or 2 days a week of hunger + quickly visible results.


Please enter your comment!
Please enter your name here